1. Technical Field
The present invention relates to an electronic apparatus including an electro-optical device that uses a direct-below-type back light unit having a spacer that supports an optical member.
2. Related Art
Generally, liquid crystal display (LCD) devices include a display panel that displays an image and a back light unit that is arranged on a rear face of the display panel and irradiates light toward the display panel.
Recently, the size of the screens of the liquid crystal display devices that are commonly used as the display devices of personal computers and CAD apparatuses has increased. Accordingly, luminance that is not inferior to that of display devices using Braun tubes is required for the large-screen liquid crystal display devices.
The large-screen liquid crystal display devices are commonly used on a table, on the floor, or the like as a stationary-type device, and thus a decrease in the thickness of the liquid crystal display devices to the degree needed for a notebook computer is not required. However, in order to enhance the characteristic of the liquid crystal display devices, a decrease in thickness of an appropriate degree is required. Accordingly, as a display panel, a transmissive type is used, and as a back light unit, a direct-below-type back light unit in which a plurality of light sources are arranged right below the display panel is used.
The direct-below type back light unit is configured to emit uniform light from a plurality of light sources to a display panel by arranging the plurality of light sources formed of LEDs or the like on a bottom face of a casing in a predetermined pattern and arranging a large diffusing plate (optical member) that disperses light in an opening portion of the casing that is the emission area of the plurality of light sources.
Here, when the large-screen liquid crystal display device is vertically arranged, the large diffusing plate may be easily bent toward the bottom face of the casing under its own weight. Accordingly, technology for preventing flexure due to the weight of the diffusing plate by arranging a plurality of spacers that protrude from the bottom face of the casing on the diffusing plate so as to support the diffusing plate has been disclosed (for example, JP-A-2006-278077).
However, according to the technology disclosed in JP-A-2006-278077, the plurality of spacers is arranged uniformly on the entire area of the bottom face of the casing, and the spacers are arranged on the entire area of the bottom face of the diffusing plate to support the diffusing plate. Thus, a lot of spacers must be arranged on the bottom face, and accordingly, there is a problem from the viewpoint of the manufacturing cost of the back light unit.
In addition, when a lot of spacers are arranged on the bottom face, emission of light from the plurality of light sources that are arranged on the bottom face is blocked by the spacers. Accordingly, the optical characteristic of the back light unit may deteriorate.